In the completion of hydrocarbon wells, it is common practice to isolate one or more subterranean hydrocarbon-producing formation zones from each other within a well bore using packers. Conventional practice may include deploying a packer with a seal stinger or seal bore at a desired depth within the well bore using a hydraulic setting tool on a wireline, tubing string or the like. After the hydraulic setting tool is next retrieved from the well, an on/off tool may be lowered into the well bore on a tubing string, slid over the stinger and latched onto the top of the packer. A set of seals is typically seated inside the on/off tool to impart a fluid-tight seal between the tool and the stinger as the tool slides over the stinger and latches onto the packer.
After the on/off tool is latched to the packer, downward pressure may be applied to the tubing string to compress the tubing and approximate the compression dynamics of the production string. The compressed tubing string may then be marked at the well surface to indicate the approximate depth of the packer in the well bore. Next, the on/off tool may be unlatched from the packer and the tubing string retrieved from the well bore. The number and length of the subs in the production string may be “spaced out” or taken into account to determine the number of joints to be used in the production string according to the depth of the packer as indicated by the mark on the tubing string. Finally, the production string may be assembled at the well surface and an on/off tool coupled to the production string and inserted into the well bore until the on/off tool lands on the packer and is coupled thereto typically by rotation of the production string. A Christmas tree may then be assembled at the well surface to complete the well and hydrocarbons produced from the production string through the Christmas tree.
One of the drawbacks inherent in the conventional method of latching the on/off tool to the packer during the procedure of marking the packer depth on the tubing string is that mud, sand and other sediments tend to settle on the top of the packer and the stinger as the packer is deployed in the well bore. The presence of the sediments on top of the packer and the stinger may impede latching of the on/off tool to the packer. Consequently, repeated attempts may be required to successfully conclude the latching and marking operation as the on/off tool is raised and lowered on the stinger and makes repeated contact with the top of the packer. As the on/off tool repeatedly slides over the stinger during these attempts, the sediments tend to abrade or erode and damage the seals, necessitating frequent replacement of the seals.